Refrigeration system

ABSTRACT

A refrigeration system having a compressor and a condenser, a pipeline connected between the compressor and condenser and a filter-dryer heat exchanger connected to a high gas velocity ejector built into a pipeline between the compressor and condenser. This ejector is formed by a port through which passes refrigerant gas at high velocity. At the discharge end of this port a pipe of small diameter is inserted to the exact spot which will cause a suction to be drawn on it, thus creating the ejector effect. The suction on the small-diameter pipe causes hot refrigerant gas to be drawn from a hot gas discharge line through a filter-dryer heat exchanger of large size where the hot gas is filtered and cooled so it will change to a liquid in the small diameter pipe and be ejected back into the main hot gas line as a cool liquid refrigerant by the action of the ejector. The ejector is of large port design so as not to cause back pressure on the main refrigerant system.

United States Patent [19] Phillips 1 REFRIGERATION SYSTEM [76] Inventor: Clyde G. Phillips, 105 Maryland Ave., Westview III, Wilmington, Del. 19804 22 Filed: Sept. 13, 1972 21 Appl. No.: 288,542

52 s. CL... .Q 62/85, 62/474, 62/475 [51] Int. Cl. F251) 47/00 [58] Field of Search 62/85, 195, 474, 62/475 [56] 7 References Cited UNITED STATES PATENTS 2,119,201 5/1938 Cook 62/475 2,705,405 4/1955 Uhlman 62/474 2,767,554 10/1957 Ormes 62/475 3,070,977 1/1963 Kimmel 62/84 3,175,342 3/1965 Balogh 62/474 3,276,2l6 10/1966 Papapanu 62/475 Primary ExaminerWilliam J. Wye Attorney-Clarence A. OBrien & Harvey B. Jacob- Jan. 8, 1974 [5 7] ABSTRACT A refrigeration system having a compressor and a condenser, a pipeline connected between the compressor and, condenser and a filter-dryer heat exchanger connected to a high gas velocity ejector built into a pipeline between the compressor and condenser. This ejector is formed by a port through which passes refrigerant gas at high velocity. At the discharge end of this port a pipe of small diameter is inserted to the exact spot which will cause a suction to be drawn on it, thus creating the ejector effect. The suction on the small-diameter pipe causes hot refrigerant gas to be drawn from a hot gas discharge line through a filterdryer heat exchanger of large size where the hot gas is filtered and cooled so it will change to a liquid in'the small diameter pipe and be ejected back into the main hot gas line as a cool liquid refrigerant by the action of the ejector. The ejector is of large port design so as not to cause back pressure on the main refrigerant system.

7 Claims, 1 DrawingFigure 1 REFRIGERATION SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to refrigeration systems, and in particular to systems for units of relatively small capacity such as are commonly mounted in windows and the like for cooling individual rooms.

2. Description of the Prior Art I The increased use of refrigeration units for cooling buildings and other structures has resulted in the development of relatively small capacity units capable of being movably arranged in openings such as windows and the like. The versatility and ease of installation of this type of unit is particularly advantageous for applications involving structures that do not have a central forced-air heating system which may be converted to cooling.

A problem encountered with these window units, however, involves filtration of the refrigerant. It is in general not possible to use the filter-dryer heat exchangers used in the liquid line of larger units, because an excess of liquid refrigerant would build up in the system pipelines preventing the system from balancing between starting and stopping. The systems compressor would not cycle on the thermostat, but would rather cycle on the systems overload relay. A delay of five or six minutes would result for the high pressure and low pressure sides of the system to balance. Accordingly, mesh-type filters are now used on the small refrigeration units; although these filters still add a pressure drop to the system which decreases its efficiency.

The advantage of using a filter-dryer heat exchanger in a refrigeration system is that such a filter-dryer will purify the refrigerant and lubricating oil by continually removing dirt particles down to a microus size, and by removing any acid and moisture. The mesh screens conventionally used on window units do not remove the acid and moisture from the system, and do not purify the refrigerant and lubricating oil. The presence of these impurities in the system will, for example, decrease bearing life in the compressor and the like.

SUMMARY OF THE INVENTION It is an object of this invention to improve upon a refrigeration system using a capillary restrictor tube that separates the high from the low side of the system. The improvement is made by the use of a filter-dryer heat exchanger and an ejector that causes a portion of the refrigerant in the refrigeration system to pass through the system without adding any pressure drop to the sys tem as a whole. The filter-dryer heat exchanger acts as an auxiliary condenser, an oil purifier, and a refrigerant purifier. It is several sizes larger than any filter dryer now used on capillary tube systems.

The liquid refrigerant from the filter-dryer heat exchanger is'drawn into the main hot gas stream by use of a conventional ejector that utilizes the velocity of the refrigerant gas.

This liquid refrigerant flashing into the main hot gas line increases the BTU output per watt of electricity used by 25 percent to,30 percent, and prolongs the life of the machine to a great extent. A refrigeration system used under full load or overload gets hot enough for water to start to form in the refrigeration system. This in turn causes acid in the oil and refrigerantleading to motor burn out. In the system according to the present invention the refrigerant system runs cooler and continually takes water and acid out of the system. With the provision of the auxiliary condenser, the system runs cooler. I

'BRIEF- DISCRIPTION OF THE DRAWINGS The sole FIGURE is a partly schematic, vertical longitudinal sectional view showing a refrigeration system according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularly to the drawing, a refrigeration-system 10 according to the present inventionwhich may be similar to a conventional window unit'-has a housing 12 in which is arranged a conventional compressor 14 and heat exchanger 16. Assuming that system 10 is a refrigerant compression system, heat exchanger 16 is a refrigerant condenser. A pipeline 18 having an enlarged portion 20 is connected to compressor l4 and heat exchanger or condenser 16 for providing a refrigerant gas passage 22 therebetween; The portion of line 18 between compressor 14 and portion 20 is intended for hot gas discharge, and is of a size commonly used in conventional refrigeration systems. A filter-dryer heat exchanger 24 is connected to portion 20 for filtering, drying, and condensing a refrigerant passing between compressor 14 and condenser l6.

Enlarged portion 20 is provided with a standard ejecto'r used on high velocity gas. ,Filter-dryer 24 is arranged with use of a high velocity ejector in passage 22'. The use of the high velocity gas ejector 26 results in the refrigerant being drawn through filter-dryer 24 without any pressure drop that can be charged to the overall system. Advantageously, large portion 20 is similarto, for example, the Fisher Companys high velocity gas ejector marketed under the name Airjector," and the inside diameter of the high velocity gas port 26 is larger than the inside diameter of that portion of pipeline 18 between compressor 14 and portion 20. Thisdimensioning will ensure minimum pressure drop across the high velocity gas ejector. Connection of filter-dryer 24 to large portion 20 is achieved by means of a pipeline 28 which passes hot discharge gas from compressor 14 to filter-dryer 24, and a capillary tube 30 connected to large portion 20 between condenser 16 and high velocity gas port 26 and to filter-dryer 24. The function of capillary tube 30 is to act as a restrictor to condense hot refrigerant. The section of enlarged portion 20 downstream of the ejector forms a mixing chamber 32 changer 36, which is inturn connected to compressor 14 as by a pipeline 38. In a vapor compression system, pipeline 34 is a liquid line passing the refrigerant to a conventional capillary tube 40, while pipeline 38 would be a suction line to compressor 14. Heat exchanger 36 would be, of course, an evaporator. Capillary tube 40 may be of the same diameter as on standard window refrigeration units, except that it may be shortened by one third when used in system 10.

A motor 42 is preferably mounted in housing'l2, and is provided with shafts 44, 46 upon which respective fans 48, 50 are mounted for rotation by motor 42. In

a refrigeration compression system, fans 48, 50 would be condenser and evaporator fans, respectively. A dividing partition 52 may be arranged in housing 12 as is conventional on window refrigeration units.

So as to enable it to efficiently function as a heat exchanger, fins 54 may be attached to filter-dryer 24 as by, for example, soldering.

The operation of refrigeration system will now be explained with the assumption that this system 10 is a refrigeration compression system in the form of a modified manufactured unit.

Hot gas passes from compressor 14 through the adjacent portion of line 18 to enlarged portion 20. The segment of pipeline 18 between compressor 14 and enlarged portion 20 is of a standard size, and passage 22 in enlarged portion 20 may be of the next larger size to pipeline 18. A portion of the hot gas passes through pipeline 28 to filter-dryer 24 by the use of a high velocity gas ejector. The remainder of the hot gas goes through the high velocity ejector port 26, the internal diameter of which may be the same size as the internal diameter of the compressor discharge portion of pipeline 18. The hot gas will be drawn through filter-dryer 24 by the action of the gas passing through high gas velocity ejector port 26. The gas passing through filterdryer 24 is cooled and is passed into capillary tube 30. The cool gas refrigerant is changed to a cool liquid in capillary tube 30 by a process which is well known. This liquid passes from capillary tube 30 and is sprayed into mixing chamber 32 by the effect of the use of a high velocity gas ejector. The mixed cool liquid and hot gas forms a saturated warm vapor. This saturated warm vapor passes to condenser 16 where it is further cooled to a liquid and is passed to pipeline 34. From pipeline 34, the liquid refrigerant passes through capillary tube 40 and into evaporator 36. Expanded hot gas from evaporator 36 is fed back to compressor 14 through suction pipeline 38. As mentioned above, approximately one third of the original length of capillary tube 40 may be eliminated.

If the manufactured refrigeration system as received from the factory is charged with, for example, refrigerant 22, a modified system 10 may be charged with, for example, refrigerant 500. In a similar manner, if the factory charge is, for example, refrigerant 500, the modified system 10 may be charged with, for example, refrigerant 12.

Due to the presence of filter-dryer 24 in system 10, the life of the system may be increased by as much as, for example, 50 per cent. The compressor bearings (not shown) will last indefinitely because the oil which lubricates them will be purified and free of acid and moisture. Further, the heat of compression will be lowered by, for example, 20 percent to 30 percent due to lower compression discharge temperature and pressure achieved by the use of, for example, refrigerant 500 in a system originally designed for refrigerant 22 and, for example, the use of refrigerant 12 in a system designed for refrigerant 500. It is to be understood, of course, that other refrigerants may be employed in a similar manner.

Capillary tube 30 controls the flow rate of refrigerant through filter-dryer 24 so that cool refrigerant is injected into the hot gas stream downstream of high gas 6 ejector port 26. Some of the liquid refrigerant passing from capillary tube 30 will flash into vapor and absorb latent BTUs of heat from the hot gas.

The shortened length of capillary tube 40 as compared to the original equipment length will allow system 10 to balance out 25 to 50 percent faster than the original unit. Capillary tube 40 may be shortened because of the high quantity of BTUs absorbed immediately downstream of high gas velocity ejector port 26 by the latent heat of vaporization of the liquid refrigerant injected into mixing chamber 32 from filter-dryer 24. Result of this absorption is a saturated vapor which is cooled in condenser 16. In effect, condenser 16 acts as a sub-cooler to liquefy the refrigerant.

A system 10 according to the present invention permits, for example, 20 percent to 30 percent more BTUs of cooling per watt of electricity consumed. This is partially due to the ability to use, for example, refrigerant 500 in a system originally designed for, for example, refrigerant 22, because the system 10 refrigerant can be circulated faster with less power consumption, and the action of the ejector to draw refrigerant through heat exchanger 24.

The filter-dryer heat exchanger 24 functions as an auxiliary condenser without adding a pressure drop to the system. Further, filter-dryer 24 will help eliminate moisture and contamination from the system. By keeping the lubricating oil and system refrigerant pure and dry, the life of the system will be prolonged.

A system 10 according to the present invention can be employed on all refrigeration systems, particularly those using capillary tubes 40. It may be used both on house refrigerator units and freezers of, for example, l/8th of a ton to 1 ton. Further, all refrigeration units from window units to central air conditioning systems using capillary tubes such as tube 40 with a capacity up to 5 tons may be modified according to the present invention. Finally, all commercial refrigeration units where capillary tubes are employed in the system may be modified according to the present invention in capacities from l/8th of a ton to 5 tons. In the relatively small units of, for example, l/8th to 1/2 ton, either refrigerators or freezers, system 10 according to the present invention will work on, for example, refrigerants 12, 22 and 500, depending on original factory design.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. A refrigeration system comprising, in combination:

a. a compressor;

b. a heat exchanger;

c. means connected to the compressor and heat exchanger for providing a refrigerant passage therebetween;

d. means connected to the passage means for filtering a refrigerant passing between the compressor and heat exchanger; and

e. an ejector for causing refrigerant to flow through the filtering means.

2. A structure as defined in claim 1, wherein a capillary tube is connected to said passage means between 6 said heat exchanger and a port discharge of the ejector, 7. A method for filtering, drying and liquefying a reand to the filtering means for controlling the fluid flow frigerant, comprising the steps of: thr ugh the filtefa. using a standard high velocity gas ejector between 3. A structure as defined in claim 2, wherein the fila compressor and a cooling heat exchanger. termg means is a final-dryer heat exchanger 5 b. diverting hot refrigerant gas upstream from a port 4. A structure as defined in claim 3, wherein said heat exchanger is a vapor condenser.

5. A structure as defined in claim 1, wherein the filtering means is a filter-dryer heat exchanger.

6. A structure as defined in claim 1, wherein said heat 10 j exchangeris a vapor condenser. I

of the ejector to a filter-dryer heat exchanger; and c. mixing fluid from the filter-dryer heat exchanger with undiverted refrigerant gas downstream of the 

1. A refrigeration system comprising, in combination: a. a compressor; b. a heat exchanger; c. means connected to the compressor and heat exchanger for providing a refrigerant passage therebetween; d. means connected to the passage means for filtering a refrigerant passing between the compressor and heat exchanger; and e. an ejector for causing refrigerant to flow through the filtering means.
 2. A structure as defined in claim 1, wherein a capillary tube is connected to said passage means between said heat exchanger and a port discharge of the ejector, and to the filtering means for controlling the fluid flow through the filter.
 3. A structure as defined in claim 2, wherein the filtering means is a filter-dryer heat exchanger.
 4. A structure as defined in claim 3, wherein said heat exchanger is a vapor condenser.
 5. A structure as defined in claim 1, wherein the filtering means is a filter-dryer heat exchanger.
 6. A structure as defined in claim 1, wherein said heat exchanger is a vapor condenser.
 7. A method for filtering, drying and liquefying a refrigerant, comprising the steps of: a. using a standard high velocity gas ejector between a compressor and a cooling heat exchanger; b. diverting hot refrigerant gas upstream from a port of the ejector to a filter-dryer heAt exchanger; and c. mixing fluid from the filter-dryer heat exchanger with undiverted refrigerant gas downstream of the ejector. 